The present invention relates to a network monitoring device, a network monitoring method and a network monitoring program for monitoring a state of a communication network.
Recently, to assure quality of services provided through a network, the need to monitor the state of the network so as to manage the performance and quality of the network is increasing.
For example, as a method of monitoring a network, there is one in which a dedicated device for collecting communication data is placed at a specific point on a network and all the data passing through the dedicated device are collected and analyzed.
As another method, there is for example a method in which statistical information concerning communication is collected from network devices (such as switches and routers, for example) on a network and then the collected statistical information is analyzed.
Further, there is a technique that uses information collected from a dedicated device or network devices such as ones described above, and analyzes paths or points on a network to be monitored in detail.
For example, Japanese Un-examined Patent Application Laid-Open No. 2002-368750 discloses a network analysis device that receives a message of a Service Level Agreement (SLA) evaluation result from an SLA evaluation device, and identifies network devices on a path that does not satisfy the SLA. Then, the network analysis device notifies a user that it is highly necessary to monitor the identified network devices.